One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when it's possible to plant astilbe is to use the USDA zone info for New Haven.

Planting Calendar for Astilbe

Frost tolerance for astilbe:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Astilbe do well in very little cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant astilbe in New Haven is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant astilbe and expect a good harvest is probably August. If you wait any later than that and your astilbe may not have a chance to grow to maturity. You can get started a little bit earlier by starting your astilbe indoors.

Last Frost Date

In New Haven the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that USDA zone info for New Haven is just an average and the actual date of last frost changes from year to year. Half of the time in New Haven you get surprised by a frost after April 15 so just be sure to be ready to cover your astilbe if you have one of those late frosts.

USDA Zone Info for New Haven

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in New Haven

You may be interested in your other planting guides for New Haven.